The present invention relates to fire extinguishing apparatus and more particularly to a system for extinguishing fires consuming combustible liquids or gases issuing from conduits such as pipes, gas wells, and the like.
The danger of accidental combustion of combustible liquids and gases has been recognized for many years. These fires have occurred with some frequency ever since the first oil and natural gas wells were drilled. The problem has become particularly acute with the advent of drilling techniques which allowed deeper wells which tapped combustible fluids under greater pressure.
After careful consideration of the above-noted problems and prior art solutions, the inventor herein has invented a new and improved fire extinguishing system that may be lifted and disposed over a flaming well, for example, which system includes an elongated tubular structure or body having a relatively wide lower opening to accommodate a wide variety of fire intensities, a unique valve arrangement at its uppermost extremity, and a fire retardant material exhausting structure adjacent its lower extremity. Intermediate the ends of the tubular body is a gradually reduced diameter section which causes a vacuum state at the bottom of the elongated body in order to pull the fire retardant material into the elongated cylinder and thereby prevent combustion from occurring or continuing within the cylinder. The invention is first configured to allow the full force of the flaming gushing fluids to flow through the structure before commencing the flooding of the lower area adjacent the ground with fire retardant material to prevent oxygen from supporting any combustion of the emanating combustible fluid. The valve mechanism is then gradually closed to divert the fluid back through the tubular body which acts as a pressure muffler at this point. The prior art has been investigated to determine the techniques that have been developed to overcome the above noted problems, prior to the present invention. For example, in U.S Pat. No. 1,520,288 a device is disclosed for extinguishing fires in oil wells that is adapted to fit over the mouth of a well and carries chemicals for extinguishing the flames with means for forcing the chemicals from it after it is put in place. The device includes a cone-shaped body which is formed of boiler plate or the like, with inner and outer walls forming a chamber, and has an upper outlet pipe to allow some of the pressure created by the burning oil or gas to escape while the same is being put in position and thus facilitate the placing of the device over the well. The inner wall of the body has a plurality of openings which are closed by plugs of soft material so that when steam, air, or water is forced into the chamber between the double walls, the soft plugs will be expelled and the chemicals driven from the chamber against the flames to extinguish the same.
U.S. Pat. No. 1,807,498 shows a well capping device adapted for use in capping gushing oil or gas wells. The device includes a bell-shaped cap having an outlet pipe, cement or other adhesive material inlet pipes, and an inner chamber defining lip structure. The cap is placed over a well casing and the area is sealed with cement or the like through a feed line pipe, while the force of the well is allowed to vent through the discharge pipe. A valve is provided at the top of the discharge pipe so that when any fire exciting from an upper fire pipe extending upwardly from the valve is extinguished by the closing of this fire pipe valve, valves in two horizontal lead-off pipes may be opened to provide paths for the oil to flow to storage facilities.
U.S. Pat. No. 2,082,216 discloses a fire extinguishing apparatus that basically consists of a pipe having a control valve, an upper outlet end, and a lower end that is shaped to telescope with the upper end of a well pipe. The pipe is swung over the well while the well is burning and is then lowered into telescopic relation with the upper end of the pipe. In order to protect the workmen from intense heat, a shield is secured around the pipe. Also, a pipe clamp is provided in order to secure the pipe onto the well pipe. The shield is positioned at an angle to deflect flames away from workmen, who can close the valve once the joint at the clamp is cemented securely by the flow of such material into the joint by opening a supply valve leading to an inlet pipe.
U.S. Pat. No. 2,096,970 involves a means and method for extinguishing oil well fires, and includes an elongated conduit capable of conducting water under pressure, a lower end for fitting on top of a well pipe, a water feed pipe with joints for providing the water to the interior of the conduit or pipe, an upper hole, and a slot in the upper portion of the pipe fitted with a pulley for lowering a conventional explosive torpedo toward the bottom of the pipe for exploding when it is in a proper position.
U.S. Pat. No. 3,887,011 shows a fire extinguisher for extinguishing an oil well fire that has a first pipe connectable to a well pipe and a second pipe branched from the first pipe in saguaro-like fashion. The first pipe is provided with a normally open first valve and a second flap-valve, while a normally-closed third valve is provided in the second pipe. The valves are coupled together by a linkage arrangement to provide a particular operation. Also, hooks are fabricated from meltable material such as lead which melt when heated sufficiently to produce certain unattended functions designed to extinguish a fire. In order to extinguish a fire, this apparatus first closes off the upper valve where the flame exists, at which time the fluid in the apparatus is diverted by the valving to the horizontal pipe leading to a storage tank, for example.
U.S. Pat. No. 4,194,570 covers a flow momentum reversing fire abatement system for extinguishing fires in well, pipes, or vent stacks. The apparatus comprises an extinguisher body having an inlet end and an outlet end that has a cylindrical passageway or bore from the inlet to the outlet ends. The inlet and outlet ends are adapted to be coupled in a fluid tight connection with the opposing ends of a combustible fluid pipe. A diffuser cone is disposed within the extinguisher body bore in coaxial alignment with the apex towards the outlet end of the extinguisher body. An extinguisher fluid nozzle is mounted within the body bore pointed at the top of the diffuser cone. Carbon dioxide, nitrogen, or helium may be used as an extinguishing fluid flowing through the nozzle.
U.S. Pat. No. 4,337,831 is a fire extinguishing apparatus for oil wells that has a plurality of containers that contain fire extinguishing material under pressure and that are connected to a main fire extinguishing container. The main container has a conduit leading from a valve in the neck thereof to the interior of a bell nipple positioned on an oil well blow out preventor. The valve has a vertically reciprocatable plunger therein, which when actuated downwardly permits free flow of the fire extinguishing material contained in the several containers to flow through a valve outlet leading to the bell nipple.
U.S. Pat. No. 4,433,733 shows an oil storage tank extinguisher or snuffer for putting out fires in oil tanks or oil wells which consists of a framework made from vertical members which are joined together at the bottom by a circular frame member and at the top by a similar frame member. The frame is designed to withstand fire for a sufficient period of time to extinguish the fire and is covered by a flexible material such as asbestos having cylindrical side walls and a top. A fire retardant fluid may be injected within the snuffer if desired by means of nozzles, for example. If there is an excessive build up of liquid within the chamber, it can be drawn off through a line.
And U.S. Pat. No. 4,899,827 discloses an oil well fire control system by injecting pressurized carbon dioxide, nitrogen, or monoammonia phosphate, into the flow of hydrocarbons from the drill pipe and casing through a spool apparatus located above the casing. Untreated water may be used as a back-up fluid after the chemicals have been dissipated.
From the foregoing it should be clear that none of the prior art techniques provide the adjustable valve/fire retardant flooding combination technique of the invention. Thus, it should be recognized that a fire extinguishing apparatus that is relatively easily positioned over even a very high pressure gushing and flaming oil well and the like before applying a combination of its features that quickly extinguishes all flames that exist at the well site and prevents re-ignition, constitutes an important advancement in the art.